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September 22, 2012, 10:11 PM | #26 |
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Good summary.
32.174 is a better approximation for G (the number of pounds in a slug) than 32.163, but it won't really change the results from a practical standpoint.
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September 22, 2012, 10:20 PM | #27 |
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Yeah... I seen both numbers being used... the 32.163 is the older one I believe.
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September 22, 2012, 10:21 PM | #28 |
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marine6680,
Yours, even with the slight numerical correction offered by JohnKSa, is one of the better perspectives on the topic that I've seen in a long time. Nice job and thanks for splitting the paragraphs like you did- nice 'n easy on these old eyes. Nicely done.
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September 22, 2012, 10:28 PM | #29 |
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I try, thanks.
I'll edit to include the new figure. |
September 22, 2012, 10:43 PM | #30 |
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@ marine6680-
What you've said agrees with the vast majority of what I've read (MacPherson, Schwartz, Fackler, Roberts, et. al.) so far about the topic. Hell, I'm impressed- maybe you missed your calling.
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September 22, 2012, 10:58 PM | #31 |
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I was in college for engineering.
Ended up in aviation as electrical and avionics. |
September 22, 2012, 11:23 PM | #32 | |
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Quote:
To be sure my I like my big magnums, it is just easier to conceal and more practical to carry a Glock for SD.
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September 22, 2012, 11:30 PM | #33 | |
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Quote:
There are plenty of other factors- ballistic and otherwise- that are as important, or more important. |
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September 22, 2012, 11:34 PM | #34 | |
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Marine6680,
I agree with most everything you posted, it is difficult to argue physics. However, Quote:
I believe that is why historically the 125 Grain 357 magnum at 1350-1450 FPS and the 115 grain 9mm +P+ at the same velocity seem to defy logic as they perform poorly in gelatine, but work wonderfully on the street. The 180 Grain 44 Magnum fits into this category as well.
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September 22, 2012, 11:45 PM | #35 |
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Nanuk, what of the case where the LEO put several 125 JHP .357 into the torso of a large male, but all created shallow wounds, and large male got lucky hit on LEO with mousegun, severing artery.? (I remember the account, but not the names.)
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September 23, 2012, 01:07 AM | #36 |
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Not all rifle rounds are created equal and neither are pistol rounds. But on average... the statement about velocity is true.
It is a combination of velocity, size, shape... Heavier bullets can do well at lower velocities, usually because they are larger diameter caliber. Flat bullets cavitate more than pointed... but there is a floor below which standard readily available bullets will not create large cavitation in relation to their size. This ratio of cavitation size to bullet size is important. Even a golf ball will cavitate, and at relatively low velocities compared to a bullet. But that is in plain water, and penetration would be low. Which is another problem... shallow cavitation. Which is what handgun hollow point rounds do. They expend most of their energy quickly in the first few inches, then its just direct displacement damage after that until it stops. And they can't just redesign to slow down the expansion rate, as then what little cavitation there is would be spread out and it wouldn't be as effective at causing pain. 22lr hyper velocity hollow points are another example, massive cavitation in relation to their size, but very shallow. I would say the 1300fps mark may be close to the lower end of velocity that gives good cavitation across a good range of bullet shapes and types... 1300-1400fps seems about right, from the tests I have seen of the 22lr mini mags at 1200fps and velocitors at 1400fps. The difference between them is interesting. Last edited by marine6680; September 23, 2012 at 01:16 AM. |
September 23, 2012, 10:03 AM | #37 | |
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Quote:
Second, muzzle energy is related to velocity, but it is also related to bullet weight. If you have two rounds of equal caliber (diameter) and equal velocity, the one using the lighter bullet will carry less energy. Recognizing that, your comment makes no sense because it ignores the third variable in the equation. But the OP didn't ask anything about bullet weight -- he asked if we consider velocity or muzzle energy to be more important. Of those two, I think muzzle energy is the more important. Muzzle energy can be achieved by using heavy bullets going slow, or light bullets going fast. He didn't ask about that, so I didn't try to answer a question that wasn't asked. |
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September 23, 2012, 10:16 AM | #38 |
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AB, I think what 481 was saying that while energy goes up in direct proportion with an increase in mass, it goes up as the square of a velocity increase.
Twice the mass, twice the energy. Twice the velocity, four times the energy. So, if energy is the overriding concern, the answer will typically be to increase velocity, rather than mass. Momentum goes up in linear fashion with both mass and energy. The resistance of a medium to a bullet will be a function of energy. Look at what happens, for instance, when fast moving objects hit the water. The momentum of the bullet is what will fight the drag from the medium. The slower, heavier bullet will have the advantage. |
September 23, 2012, 10:46 AM | #39 | |
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You are thinking of trooper Coates from South Carolina. http://www.odmp.org/officer/420-troo...hunter-coates\ http://www.youtube.com/watch?v=2ca-PAWBMnk I do not believe they were shallow wounds, they just did not hit anything vital. If you watch the video you can see the fight, imagine the difficulty in placing the shot. The BG placed the trooper in a bear hug and fired his 22 into the troopers armpit. It was actually the 145 Grain STHP that trooper Coates was using.
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September 23, 2012, 11:23 AM | #40 | ||
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Quote:
Quote:
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September 23, 2012, 03:48 PM | #41 | |
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Quote:
Shot placement is THE most important thing to consider. 'Energy' and velocity are not the same thing at all and cannot be compared. Maybe energy and momentum, but not velocity. Deaf
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September 23, 2012, 08:45 PM | #42 | |
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Nanuk wrote:
Quote:
My load was 25.0 grs. of Dupont (then) IMR-4227 with a 245 gr. cast SWC, Lyman #429421. Out of my 7 1/2" Super Blackhawk it clocked right on at 1400 fps MV. The range was 40~50 yards. Bob Wright |
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September 24, 2012, 11:19 AM | #43 | |
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From Nanuk:
Quote:
tipoc |
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September 24, 2012, 02:56 PM | #44 | |
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Quote:
As for the rest of the discussion, there are a lot of variables but ultimately it comes down to 2 things. How much energy does a round have and how effectively can it transfer that energy into the target. I shake my head every time someone says bigger and slower is better. If that was true, a 45 would be more effective than a 30-06 and that is obviously not the case. How many here would consider a 5.56 rifle a better weapon than a 45? Probably most of you and rightfully so. How about a 357 magnum vs a 45? Assuming a bullet is placed in the right spot and will transfer it's energy effectively, the round with more energy will do more damage and stop the target more effectively. Now, assuming the energy of two rounds is equal, I would bet on the bigger bullet to transfer it's energy effectively.
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September 24, 2012, 03:19 PM | #45 |
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SRH78, you assume the round with more energy will also be properly configured to have adequate penetration. This is not always true.
If the round uses a bullet that will penetrate, then yes the higher energy round should have an advantage. |
September 24, 2012, 04:23 PM | #46 |
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The proper amount of penetration is certainly part of transferring energy effectively.
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September 24, 2012, 05:16 PM | #47 |
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The will to pull the trigger and put whatever ballistics into play.
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September 24, 2012, 06:59 PM | #48 |
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I believe any premium JHP ammo available will do the job nicely. After that, practice, practice, and more practice. The more capable you are with your weapon the less you will worry about what type of bullet you use or its velocity. Bullet placement and multiple hits will do worlds more than any difference in velocity, energy, or momentum.
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September 24, 2012, 09:51 PM | #49 | |
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Quote:
There's no real comparison between a rifle cartridge at 2500 to 3500 fps and handgun cartridges at 800 to 1300 fps. At the range of velocities of most handgun ammunition, and given the elasticity of the target, there's simply not enough energy to make much difference. For common handgun cartridges, effectiveness for self defense applications will be related to (1) how big a hole the bullet makes; (2) the bullet penetrating deeply enough to hit something important; and (3) the shot being placed well enough to hit something important.
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September 24, 2012, 11:52 PM | #50 |
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Apples, oranges, pear, grapefruit, or whatever, they still do more damage as a result of the increased energy they are able to transfer effectively to the target.
Besides, you don't have to get to 2500 to 3500 fps to see a difference and some common handguns exceed the 1300 fps you mentioned. Case in point, 357 magnum vs 45 ACP. If the difference in velocity and thus difference in energy didn't matter then the 45 would be a much more potent cartridge. Does anyone honestly believe it is? I can tell you this, a 45 Colt and 454 Casull shoot the same diameter bullet and neither shoots 2500 fps but the difference on game is like night and day. With the Colt, I can shoot cottontails and eat right up to the bullet hole. With the Casull, there isn't much left of a jackrabbit. A 45-70 at 1700-1800 fps with a soft nosed bullet will leave a huge exit wound on a hog. There are plenty of loads for the 357 magnum, 357 Sig, 10mm, and a few others that will do 1500+ fps from a full size handgun. These handguns also aren't shooting a little 22 caliber bullet. Here is another point. Lets compare 380 and 9mm. Because of it's increased energy, the 9mm's bullets can be made to expand more and still penetrate to a sufficient depth. That is benefit of it's increased energy. The bottom line is that energy is the potential to do work. In this case the work is damage to the target. As I said earlier, IF you can transfer that energy effectively to the target then the round with more energy will be more effective. That point is not even debatable. What is debatable is which loads in which calibers in which guns actually transfer their energy effectively. I have already said that all else being equal, I would bet on the larger bullet transferring it's energy more effectively but all else is not always equal. Here is another example that may help make my point a little clearer. A baseball will have more energy than a fillet knife and it will transfer 100% of it to whatever it hits but the filet knife will transfer it's energy much more effectively. Effective, as I am using it doesn't simply mean energy transferred to the target but energy transferred to the target as damage.
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